<template>
  <div class="app-container">
    <el-input
      v-model="filterText"
      placeholder="Filter keyword"
      style="margin-bottom: 30px;"
    />

    <el-tree
      ref="tree2"
      :data="data2"
      :props="defaultProps"
      :filter-node-method="filterNode"
      class="filter-tree"
      default-expand-all
    />
  </div>
</template>

<script>
export default {
  data() {
    return {
      filterText: '',
      data2: [
        {
          id: 1,
          label: 'Level one 1',
          children: [
            {
              id: 4,
              label: 'Level two 1-1',
              children: [
                {
                  id: 9,
                  label: 'Level three 1-1-1',
                },
                {
                  id: 10,
                  label: 'Level three 1-1-2',
                }
              ]
            }
          ]
        },
        {
          id: 2,
          label: 'Level one 2',
          children: [
            {
              id: 5,
              label: 'Level two 2-1',
            },
            {
              id: 6,
              label: 'Level two 2-2',
            }
          ]
        },
        {
          id: 3,
          label: 'Level one 3',
          children: [
            {
              id: 7,
              label: 'Level two 3-1',
            },
            {
              id: 8,
              label: 'Level two 3-2',
            }
          ]
        }
      ],
      defaultProps: {
        children: 'children',
        label: 'label',
      }
    }
  },
  watch: {
    filterText(val) {
      this.$refs.tree2.filter(val)
    },
  },

  methods: {
    filterNode(value, data) {
      if (!value) return true
      return data.label.indexOf(value) !== -1
    },
  }
}
</script>
